7.2.4 Driving Capacitive Loads

Capacitive output loading applications will benefit from the use of a series output resistor R_OUT. Figure 28 shows the use of a series output resistor, R_OUT, to stabilize the amplifier output under capacitive loading. Capacitive loads of 5 to 120 pF are the most critical, causing ringing, frequency response peaking and possible oscillation. Figure 29 provides a recommended value for selecting a series output resistor for mitigating capacitive loads. The values suggested in the charts are selected for 0.5 dB or less of peaking in the frequency response. This gives a good compromise between settling time and bandwidth. For applications where maximum frequency response is needed and some peaking is tolerable, the value of R_OUT can be reduced slightly from the recommended values.

Figure 28. Decoupling Capacitive Loads

Figure 29. Suggested R_OUT vs Capacitive Load

Figure 30. Frequency Response vs Capacitive Load